Universal motion simulator

ABSTRACT

The present application provides a motion simulator apparatus and method of use. The motion simulator apparatus may include an anthropomorphic robot arm adapted to provide at least six degrees of freedom of movement, a user pod for receiving a user and being operatively connected to the anthropomorphic robot arm, and a haptic interface operatively associated with the user pod for providing haptic feedback to the user in correspondence with the movement of the user pod.

RELATED APPLICATIONS

This application claims priority to Australian Provisional PatentApplication No. 2006907038 in the name of Deakin University, which wasfiled on 19 Dec. 2006, entitled “Method and Apparatus for a RemoteInterface” and, Australian Provisional Patent Application No. 2007902660in the name of Deakin University, which was filed on 18 May 2007,entitled “Method and Apparatus for Motion Simulation” and AustralianProvisional Patent Application No. 2007903796 in the name of DeakinUniversity, which was filed on 13 Jul. 2007, entitled “Haptic Control”and the specifications thereof are incorporated herein by reference intheir entirety and for all purposes.

FIELD OF INVENTION

The present invention relates to the field of remote interfacingutilising haptic technology. “Haptic” refers to the sense of touch, and,as such any technology that creates a sense of touch or, generallysensory feedback sensation(s) to a human operator can be classified ashaptic technology.

BACKGROUND OF INVENTION

Throughout this specification the use of the word “inventor” in singularform may be taken as reference to one (singular) or all (plural)inventors of the present invention. The inventor has identified thefollowing related art.

In general, the field of haptics relates to the development, testing,and refinement of tactile and force feedback devices and supportingsoftware that permit users to sense, or “feel”, and manipulate virtualobjects or an environment with respect to such attributes as shape,weight, surface textures, temperature and so on.

Generally, it may be stated that of the five senses, namely, sight,sound, smell, touch and taste, it is sight, sound and touch that providethe most information about an environment, where the other senses aremore subtle.

In humans, tactile sensing is generally achieved by way of receptorcells located near the surface of the skin, the highest density of whichmay be found in the hands. These receptors can perceive vibrations of upto about 300 Hz. Therefore, in a haptic interface tactile feedback maygenerally involve relatively high frequency sensations applied in theproximity of the surface of the skin, usually in response to contact, assuch, between a user and a virtual object. In contrast, the humansensing of forces may be considered as more kinesthetic in nature, andmay ordinarily be achieved by receptors situated deeper in the body.These receptors are located in muscles, tendons and joints and may bestimulated by movement and loading of a user's body parts. The stimulusfrequency of these receptors may be much lower, lying in the range ofabout 0-10 Hz. Accordingly, in a haptic interface force feedback maycomprise artificial forces exerted directly onto the user from someexternal source.

Therefore, it may be considered there are two aspects to the sense oftouch; firstly that which provides kinesthetic information and secondlythat which provides tactile information. The kinesthetic informationthat a user perceives about an object are coarse properties such as itsposition in space, and whether the surfaces are deformable or resilientto touch. Tactile information may be considered to convey the texture orroughness of an object being ‘touched’. It is desirable that both typesof ‘touching’ information be used in a realistic haptic interface.

Haptic Interfaces are systems that enable a user to interact with avirtual environment by sensing a user's movements and then relaying thisinformation to the virtual environment. Along side this interaction,sensory feedback is provided to the user which reflects their actionswithin this environment, and as a result, it is the design of the hapticinterface which conveys the level of sensory interactivity between theuser and the virtual environment.

A device developed by M.I.T and SensAble Technologies, Inc, is calledthe PHANToM™ (Personal Haptic Interface Mechanism) interface, which islargely used in the field of computer haptics. The PHANToM™ interfacemay allow a user to feel the forces of interaction that they wouldexperience by touching a real version of an object with a pencil or theend of their finger.

A majority of haptic devices are desktop devices, such as those soldunder the PHANToM™ range including the PHANToM Omni™ and PHANToMPremium™. Other devices are generally wearable ones such as gloves andhaptic body suits and may have high degrees of freedom and consequentlyare very expensive. Lower cost haptic devices are usually desktopdevices as they have less controlled/actuated degrees of freedom (DOF)compared to their total DOF. For example, the PHANToM Omni™ has 6 DOFhowever only 3 of those are actuated and therefore this device isconsidered to only provide limited interactivity, i.e. sensors areeasier and cheaper to install than motors. Accordingly, at present,certain lower cost haptic devices marketed under the PHANToM™ brandexhibit a force feedback which is only available to three degrees offreedom, namely, in the linear dimensions (x, y, z) out of the sixcomplete degrees of freedom.

During the design stage of a haptic interface, one needs to determinethe number of sensors and actuators to be used on the interface so thatthe level of interaction provides for the highest quality forcefeedback. In existing interface designs, the inventor is witnessing theuse of a larger sensor to actuator ratio, which results in a highlyinteractive dimensional experience, but is reduced in the level ofsensory feedback. The introduction of larger sensor numbers is mainlydue to the difficulties in designing a completely transparent forcefeedback system with high degrees of freedom. Another contributor is thelow-cost factor to commercial implementation of more sensors overactuators.

Transparency allows a user to feel realistic forces without adjusting tomechanical issues such as backlash and the weight of the interfaceitself. It is therefore understandable to see higher transparencyinterfaces in a low-cost commercial system, as it utilises fewer degreesof freedom that provide force feedback. More complex devices andtherefore more expensive ones consequently offer less transparency;however provide greater usability for the requirements of rendering andinteracting with rich and complex virtual worlds.

The current low-cost interfaces have limitations that have beenrecognised to provide certain restrictions on the user from interactingwith the virtual environment. One of these restrictions is the abilityto grasp and manipulate virtual objects with sensory/force feedback.Grasping is one of the most basic abilities of human interaction, yet ithas shown to be one of the most difficult to achieve with respect tohaptic interface design.

Early attempts at simulating grasping were based on the use of two,three degree of freedom (DOF) devices. While this configuration providesa very realistic simulation, a significant amount of workspace isrequired, which is very limiting if an attempt is made to utilise adual-hand approach. There have been several attempts at developing adesktop device which is able to simulate grasping with three dimensionalmanipulation and force feedback, however the majority of these deviceshave depicted tools such as laparoscopic or endoscopic tools forminimally invasive surgery. In view of this it would also be desirableto provide a device which is capable of being adapted to differentapplications.

The interactive performance of the PHANToM™ device relies on a singlepoint of interaction with the virtual or tele-manipulated environment.Attempts have been made to introduce multiple points of interactionthrough addition of grasping mechanisms with force feedback to a hapticdevice. This approach allows for the extension of grasping with forcefeedback, the addition of motion and force feedback with three degreesof freedom. Typically such additions may comprise the drive motor(s) andpulley system(s) required for the gripping function to be included onthe end of the haptic device which adds extra weight to the system andresults in diminishing overall performance.

One potential solution to the above problem, in relation to a singleidealized pair of “soft fingers” (ie a point contact with friction)where no internal torsion is exerted on an object during grasping, is touse a single drive motor and cable pulley system which sits on the endof a haptic device¹. A single drive motor and cable pulley systemrelates to both fingertips in this design as the second fingertip feelsthe reaction force of the grasped object (it is the same as squeezing agolf ball between a thumb and index finger, the force felt on bothfingers is the same). However, it is not clearly evident that theposition of the unactuated finger is tracked. Attached to the pulley isa finger interaction point which is driven by a motor and cable system,depending on the appendage that is used to interact with the device,i.e. the thumb or index finger interface. The other finger interface (iean opposed finger for gripping) is directly coupled to the actuatedinterface, which means that both fingers will move an equal distancefrom each other and the haptic device. Consequently, to reduce theweight of the grasping interface, a small drive motor is used and as aresult the maximum force of the system is relatively small. This designmay limit the finger interfaces by not allowing the user to experienceindividual external forces applied to each finger. This design may alsobe limited in that no torque can be exhibited to the user whichultimately limits the interactive experience for a user and theapplicability of the device. ¹, K. Salisbury, R. Devengenzo. Towardvirtual manipulation: from one point of contact to four. Sensor Review,Vol 24•Number 1•2004•pp. 51-59.

The aforementioned problems are not intended to be an exhaustivereference, but rather an indication, in the view of the inventor, as tothe general weaknesses that current systems have encountered, which tendto weaken the effectiveness of previously developed grasping interfaces.

By way of example, FIG. 1a illustrates a known haptic interface system 1a having a wheeled or tracked platform 2 a and a commercially availablehaptic device 3 a such as the above noted PHANToM™ interface. The hapticdevice 3 a has a probe 5 a. Inputs to the system 1 a in the form ofoperator hand movements of the probe 5 a are translated into controlinputs to the platform 2 a which are transmitted over the communicationchannel 4 a. Application specific haptic augmentation is in turntransmitted to the operator over channel 6 a.

For example, the operator may control the motion of the platform 2 a asit explores a remote environment, aided with images from an on-boardcamera. When the platform is likely to collide with an obstacle thenhaptic augmentation in the form of appropriate forces are provided tothe operator to indicate to the operator that the robot is about tocollide with an obstacle.

The inventor has also identified the following related art. Thesimulation of motion may be broken down generally into two components,namely, fundamental forces of motion and, the body's sensation orexperience during motion. With respect to the first component offundamental forces of motion, most simulators are more or lessstationary and have no momentum therefore they must produce a force thatmoves a user to simulate a change in direction or momentum for thesimulated motion. In general, the fundamental movements of a simulatormay be considered as pitch (tilting up or down), roll (sideways rollingto the left or right) and, yaw (turning left or right within ahorizontal plane). It is desirable that a sophisticated simulator mayalso facilitate vertical, lateral and longitudinal displacement, whicheffectively provides six degrees of freedom to the system. With respectto the second component of the body's sensation of motion, it can besaid that this relates to the brain's interpretation of the experiencethrough the bodily senses. The inner ear and vision are considered toplay a major role. Sound may also have an influence on the brain'sinterpretation of motion. Also, touch or tactile sensation may provide ameans of establishing an interpreted reality of motion. Tactilesensation is generally provided by motion simulators by way of audiodrivers or vibration generators operatively associated with thestructure of the simulator itself.

There are several commercial motion simulators available such as flightsimulators. An example of simulators are those offered by Moog, Inc andits affiliated companies throughout the world using a hydraulic basedservo actuator configured in a closed chain kinematic manner, however,the motion and work envelope of these systems may be very limited.Available simulator technology may use a ‘pod’ as the simulated operatorspace to represent the physical environment between the operator and thesimulated system. In motion enabled simulation systems this pod may bemounted on a motion platform, and visual cues and motion commands may begenerated in response to the user's operation of the controls and thesimulated system's interaction with the virtual environment.

Most motion simulator systems whether flight, car, tank simulator etc,have one weakness in common. Their lack of full body motions throughmechanical constraints, for instance, is still a topic of challengingresearch for virtual environment technology. In most cases existingtechnology may use a “cabin” that represents the physical vehicle andits controls. The cabin may be ordinarily mounted on a motion platform,and virtual window displays and motion commands may be generated inresponse to the user's operation of the controls. These systems alsotend to be specialized to a particular application.

In recent years there has also been the exploitation of such technologyby the entertainment industry and adventure rides. However, for manykinds of virtual environment applications, more active self-motion maybe required. The major challenges for full body motion in a virtualenvironment arise whenever we have locomotion through a large virtualspace, locomotion over varying surface characteristics, and motion in adirection other than horizontal are required. Thus, the replication orsimulation of full body motions represents a challenging topic ofresearch in virtual environment technology.

Any discussion of documents, devices, acts or knowledge in thisspecification is included to explain the context of the invention. Itshould not be taken as an admission that any of the material forms apart of the prior art base or the common general knowledge in therelevant art in Australia or elsewhere on or before the priority date ofthe disclosure and claims herein.

SUMMARY OF INVENTION

An object of the embodiments described herein is to alleviate at leastone disadvantage associated with related art as discussed hereinabove.

In one aspect of a first embodiment described herein there is provided amethod of providing feedback to at least two user contact points of ahaptic interface, the method comprising the steps of:

remotely coupling a first and at least one second feedback actuator inoperative association with a haptic device;

actuating the first and at least one second feedback actuatorindependently of each other;

distributing feedback from the first and the at least one secondfeedback actuator to a first and at least one second user contact point,respectively.

The step of remotely coupling may comprise the step of guiding at leastone actuator cable to a central body in communication with the terminalend of a haptic device. In one form, the step of guiding may beperformed by attaching an actuator cable support plate to a central bodyin communication with the terminal end of a haptic device. The centralbody may be used to accommodate the bearings of the pulleys, andeffectively provide a means of attachment for the cable support plate.The central body also provides an attachment point to the end of ahaptic device. Through an addition of another pulley, by way ofmodifying the central body, another finger contact point may be added.

A fixing coupling may be used to facilitate the attaching of the contactpoints to the central body.

Preferably, the step of actuating comprises the steps of providing atleast one pulley and cable system for each actuator wherein each systemis adapted for providing bi-directional motion of its respective pulleyabout an axis of the central body.

It is also preferable that the step of distributing feedback comprisesthe step of operatively attaching each user contact point to itsrespective feedback actuator with at least one arm member. The at leastone arm member may be operatively attached to a respective pulley. Thestep of distributing feedback may comprise applying one or more ofinternal and external feedback to a user's fingertips.

In another aspect of the first embodiment described herein there isprovided apparatus for providing feedback to at least two user contactpoints of a haptic interface, comprising:

remote coupling means for remotely coupling a first and at least onesecond feedback actuator in operative association with a haptic device;

independent actuating means for actuating the first and at least onesecond feedback actuators independently of each other;

feedback distribution means for distributing feedback from the first andthe at least one second feedback actuator to a first and at least onesecond user contact point, respectively.

Accordingly, the remote coupling means may comprise:

guide means for guiding at least one actuator cable to a central body incommunication with the terminal end of a haptic device. The guide meansmay comprise, in one form, an actuator cable support plate attached to acentral body in communication with the terminal end of a haptic device.A fixing coupling may be used to facilitate the attachment of theactuator cable support plate to the central body. The independentactuating means may comprise at least one pulley and cable system foreach actuator wherein each system is adapted for providingbi-directional motion of its respective pulley about an axis of thecentral body. The feedback distribution means may comprise at least onearm member for operatively coupling each user contact point to itsrespective feedback actuator. The at least one arm member may beoperatively attached to a respective pulley. The feedback distributionmeans may comprise a finger pad and a finger strap for applying one ormore of internal and external feedback to a user's fingertips.

Preferably, the feedback comprises one or more of:

tactile sensation;

at least one kinesthetic force.

In at least one preferred aspect of the first embodiment there isprovided apparatus adapted to provide feedback to at least two usercontact points of a haptic interface, said apparatus comprising;

processor means adapted to operate in accordance with a predeterminedinstruction set,

said apparatus, in conjunction with said instruction set, being adaptedto perform the method steps as disclosed herein.

Preferred aspects of the first embodiment of the present invention maybe comprised of a computer program product, which in turn comprises:

a computer usable medium having computer readable program code andcomputer readable system code embodied on said medium for providingfeedback to at least two user contact points of a haptic interfacewithin a data processing system, said computer program productcomprising:

computer readable code within said computer usable medium for performingthe steps of any one of the methods steps as herein disclosed.

A feature that the first embodiment of the current invention uses issheathed actuator cables, which are routed outside the graspinginterface and are not attached to the haptic device itself. This allowsfor application to a wide range of haptic devices. An additional featureof the first embodiment of the current invention is that it employs aplurality of finger interfaces, e.g. two fingers which are independentfrom each other. Another feature of the first herebelow describedembodiment of the present invention is to provide torque feedback to theuser which results in enhanced interactivity between the user and thevirtual or tele-manipulated environment.

It is therefore desirable, in accordance with the essence of the firstembodiment of the present invention, to provide a haptic graspinginterface, which increases the number of force feedback degrees offreedom on the end of a haptic device, with its actuators mountedremotely to the grasping interface, e.g. in a box under the hapticdevice therefore making it a complete system. Such a grasping interfacewould have the advantage of being easily transferable between differenttypes of haptic devices. Such a device would also improve the currentinteractive performance of the commercially available lower cost hapticdevices and broaden their application.

The applicant sees a requirement to fill a void in the currentcommercial haptics interfaces; and the first described embodiment hereinis based on developing an extension to the current devices which willprovide the user with the ability to grasp and manipulate objects incomplex virtual environments.

In a further aspect of the first described embodiment herein there is amethod of providing feedback to at least two user contact points of aremote interface, the method comprising the steps of:

remotely coupling a first and at least one second feedback actuator inoperative association with a remote device;

actuating the first and at least one second feedback actuatorsindependently of each other;

distributing feedback from the first and the at least one secondfeedback actuator to first and at least one second user contact points,respectively.

In yet another aspect of the first described embodiment herein there isapparatus for providing feedback to at least two user contact points ofa remote interface, comprising:

remote coupling means for remotely coupling a first and at least onesecond feedback actuator in operative association with a remote device;

independent actuating means for actuating the first and at least onesecond feedback actuators independently of each other;

feedback distribution means for distributing feedback from the first andthe at least one second feedback actuator to a first and at least onesecond user contact point, respectively.

In one aspect of a second embodiment described herein there is provideda method of simulating motion, the method comprising the steps of:

providing at least six degrees of freedom of movement to a user byoperatively associating an anthropomorphic robot arm with a user pod forreceiving the user;

providing haptic feedback to the user in correspondence with themovement of the user pod.

Preferably, the method further comprises one or a combination of thefollowing steps of:

providing a user with a perception of the simulated environment; and,

tracking the motion of the user;

The step of providing haptic feedback may comprise feeding back thetracked motion of the user to an interface for adapting the userperception of the simulated environment. Accordingly, it is preferablethat the step of feeding back comprises transforming a user view by anegative amount that compliments the tracked motion. The tracked motioncomprises one or a combination of: position in Cartesian coordinates X,Y and Z; and, orientation comprising yaw, pitch and roll. At least onemajor motion cue generated by the robot arm and corresponding to theposition and/or orientation of the pod may be provided as well as atleast one minor motion cue generated by at least one haptic actuatorprovided in the pod and operatively associated with the user, and; atleast one force feedback cue generated by the at least one hapticactuator for simulating physical phenomena encountered by the user inthe simulated environment.

Software control programmed to relate a plurality of simulatedenvironment applications may be operatively associated with a motioncontroller of the robot arm and this operative association may comprisegenerating user control signals associated with pod devices controlledby the user and comprising motion parameters and, communicating thecontrol signals to the software control for triggering motion commandsfor the robot arm.

In another aspect of the second embodiment described herein there isprovided motion simulator apparatus comprising, in combination:

an anthropomorphic robot arm adapted to provide at least six degrees offreedom of movement;

a user pod for receiving a user said user pod being operativelyconnected to the anthropomorphic robot arm;

a haptic interface operatively associated with the user pod forproviding haptic feedback to the user in correspondence with themovement of the user pod.

The apparatus may also further comprise a user control interfaceoperatively associated with the pod and robot arm for providing a userwith a perception of the simulated environment; and, tracking devicesfor tracking the motion of the user. The haptic interface is preferablyadapted for feeding back the tracked motion of the user to the usercontrol interface for adapting the user's perception of the simulatedenvironment.

Aspects of the second described embodiment of the present invention alsocomprise apparatus adapted to simulate motion, said apparatuscomprising:

processor means adapted to operate in accordance with a predeterminedinstruction set,

said apparatus, in conjunction with said instruction set, being adaptedto perform one or a combination of the method steps as disclosed herein.

In a further aspect of the second described embodiment of the presentinvention there is a computer program product provided comprising:

a computer usable medium having computer readable program code andcomputer readable system code embodied on said medium for simulatingmotion within a data processing system, said computer program productcomprising:

computer readable code within said computer usable medium for performingone or a combination of the method steps disclosed herein.

In essence, aspects of the second embodiment of the present inventionstem from the realization that providing a full body motion through theX, Y, and Z planes of the Cartesian coordinate system at any orientationin combination with haptic feedback, the amount of physical realism orsuspension of disbelief of a user can be significantly established bythe resultant faithful motion cues that become available. Accordingly,the second embodiment described herein may be considered to provide aUniversal Motion Simulator (UMS).

A number of advantages are provided by the second embodiment describedherein such as:

The complete system may increase the amount of physical realism, orsuspension of disbelief that can be experienced by the user as a directresult of more realistic and faithful motion cues.

It may eliminate motion sickness problems to users as a result ofreduced reliance on alignment of visual and motion cues throughcombination of translational motion to rotary motion and the use of thesame size turning radius when changing directions

The accuracy of the human motion simulation models can be highlyimproved.

Additionally, one or several research projects may be supported by thisUMS facility and aimed on increasing vehicle safety and preventingvehicle accidents, thus the proposed simulator may also offer asignificant social value.

The haptically enabled UMS facility may provide a wide variety ofadvanced simulated motions to significantly enhance the capabilities andresearch quality of collaborative research programmes.

Particular areas of research may be supported by the preferred UMSfacility, such as the following:

-   -   Electronic stability control in vehicles and awareness of        loss-of-control situations    -   Drivers fatigue analysis    -   Improving safety of all terrain vehicles on farms    -   Effects of motion on speed and accuracy of the driver reach    -   Real-time vehicle dynamics

In contrast to certain related art systems described above, the presentspecification discloses, in accordance with a third embodiment, a newuse for haptic augmentation which we refer to as “input-control hapticaugmentation”.

According to one aspect, a third embodiment of the present inventionprovides a system in which haptic augmentation to an operator comprisesa first type of haptic augmentation which indicates to the operator thestate of a control input to a controlled device.

It is preferred that the controlled device of the third describedembodiment comprises a mobile platform.

It is preferred that the control input comprises at least one of:

a commanded linear velocity; and

a commanded angular velocity.

It is preferred that the first type of haptic augmentation to theoperator comprises a virtually-rendered three-dimensional surface.

It is preferred that the virtually-rendered three-dimensional surface:

in a first dimension, represents a first component of the control input;

in a second dimension, represents a second component of the controlinput; and

in which both the first and second components of the control input aremonotonically increasing functions of the value of the third dimension.

It is also preferred that the virtually-rendered three-dimensionalsurface is an inverted, hollow cone in which the height of the invertedcone extends in the third dimension.

It is preferred that the haptic augmentation to the operator furthercomprises a second type of haptic augmentation.

It is preferred that the second type of augmentation is applicationspecific haptic augmentation. In such a case, it is also preferred thatboth the first type and the second type of haptic augmentation arerendered to the operator through one virtually rendered surface.

According to another aspect, the third described embodiment of thepresent invention provides a system in which haptic augmentation to anoperator comprises a first type of haptic augmentation and a second typeof haptic augmentation. In this case, it is preferred that the firsttype of haptic augmentation indicates to the operator the state of acontrol input to a controlled device.

Other aspects of the third described embodiment of the present inventionprovide corresponding processes, and implementing software for thoseprocesses embodied in machine-readable substrates.

Throughout this specification, including the claims, we use the terms:

“ASHA” as an acronym for “application-specific haptic augmentation”; and

“ICHA” as an acronym for “input-control haptic augmentation”.

Other aspects and preferred features of embodiments are disclosed in thespecification and/or defined in the appended claims, forming a part ofthis description.

Further scope of applicability of the present embodiments will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments, are given by way ofillustration only, since various changes and modifications within thespirit and scope of the disclosure herein will become apparent to thoseskilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of one or more preferred embodiments willbe readily apparent to one of ordinary skill in the art from thefollowing written description with reference to and, used in conjunctionwith, the accompanying drawings, which are given by way of illustrationonly, and thus are not limiting to the scope of the present invention,and in which:

FIG. 1a is a schematic view of a known haptic interface system;

FIG. 1 is a perspective view of a haptic grasping interface inaccordance with a first preferred embodiment described herein;

FIG. 2 is an exploded perspective view of a haptic grasping interface inaccordance with the first preferred embodiment described herein;

FIG. 3 is another perspective view of a haptic grasping interface inaccordance with the first preferred embodiment described herein;

FIG. 4 is a front view of a haptic grasping interface in accordance withthe first preferred embodiment described herein;

FIG. 5 is a back view of a haptic grasping interface in accordance withthe first preferred embodiment described herein;

FIG. 6 is a side view of a haptic grasping interface in accordance withthe first preferred embodiment described herein;

FIG. 7 is a top view of a haptic grasping interface in accordance withthe first preferred embodiment described herein;

FIG. 8 is a bottom view of a haptic grasping interface in accordancewith the first preferred embodiment described herein.

FIG. 9 is a perspective view of a universal motion simulator inaccordance with a second preferred embodiment described herein;

FIG. 10 is a flow chart illustrating general feedback and control for auniversal motion simulator in accordance with a second preferredembodiment described herein;

FIG. 10a is a further detailed flow chart illustrating general feedbackand control for a universal motion simulator in accordance with a secondpreferred embodiment described herein;

FIG. 10b is a schematic block diagram of the simulator of FIGS. 10 and10 a;

FIG. 10c is a more detailed perspective view of a modified pod as shownin FIG. 9;

FIG. 11 is another perspective view of a modified pod for use with auniversal motion simulator in accordance with a second preferredembodiment described herein;

FIG. 12 is another perspective view of a modified pod for use with auniversal motion simulator showing motion capture apparatus inaccordance with a second preferred embodiment described herein;

FIG. 13 is a schematic block diagram of an operator control and mobileplatform according to a third preferred embodiment of the presentinvention;

FIGS. 14, 15 and 16 illustrate details of the embodiment illustrated inFIG. 13;

FIGS. 17 and 17 a illustrate details of the art of FIG. 1a ; and

FIG. 18 is a flow-chart illustrating aspects of the operation of theembodiment of FIG. 13.

DESCRIPTION OF PREFERRED EMBODIMENT

A first embodiment relates to a method and apparatus for providing ahaptic interface. In one particular form the present embodiment relatesto a method and apparatus for facilitating gripping of objects in ahaptic interface. It will be convenient to hereinafter describe theembodiment in relation to the use of apparatus to provide a forcereflecting haptic gripper interface to a plurality of finger interactionpoints, however, it should be appreciated that the present invention isnot limited to that application, only.

In developing the first described embodiment, two issues were consideredfor resolution. Firstly, there was the definition of the number ofvirtual fingertip points (avatars) that are required to have completeform closure (stable grasp) for the different applications of a remotegripper. Secondly there is the design of a human interface which canaccommodate these multi-point requirements. One application ofconsiderable interest is medical training such as minimally invasivesurgery. This area of haptics is becoming ever increasingly plausibledue to the fact that the haptic research community is contributing agreat deal to this area, In another field, military applications such astele-operation within dangerous environments allows for the safeassessment and disarmament of sensitive and hazardous objects. Industryapplications such as operator training allow for the safe education andtraining of employees within industry, without being prematurely exposedto dangerous work environments.

In this first preferred embodiment, a two finger device has beenconsidered as it allows for the use of minimal sensors and actuators toestablish form closure based on a grasp between the thumb and indexfinger. With fewer sensors and actuators, the device can be attached toan existing 3 DOF device and therefore provide grasping and manipulationwith force feedback while maintaining maximum possible transparency. Abenefit of this two finger design is that it allows for a torsionalforce to be applied to the user about the grasp axis, which results inan extra axis with force feedback.

A perspective view of a haptic interface in accordance with the firstembodiment is shown in FIG. 1. The interface shown has two fingergrasping contact points 13, which are systematically referred to ingeneral as gripper 1. Each contact point is independent from the otherand consequently exhibits individual forces in accordance with thispreferred embodiment of the present invention. The gripper 1 is attachedto the terminal end of a haptic device 2 by a central body 3 and fixingcoupling 4, as is further illustrated with respect to FIG. 2. Thecentral body 3 may be used to accommodate the bearings of pulleys 9, andeffectively provide a means of attachment for a cable support plate 5.The central body 3 also provides an attachment point to the end of ahaptic device 2. Through an addition of another pulley 9, by way ofmodifying the central body 3, another finger contact point 13 may beadded. The fixing coupling 4 is used to, attach the contact points 13to, in one example case the Phantom Omni™, but it can be modified to beattached to any haptic device 2.

With reference to FIGS. 1 to 8, where like reference numerals are usedfor corresponding features, attached to the central body 3 is a cablesupport plate 5, containing four sheath-end support members 6 andproviding horizontal support to two sheathed cables 7. One cable 7 foreach of the fingers 8 enters into openings (see 6 in the top view ofFIG. 7) of the sheath-end support members 6 and is wound around a pulley9, where numeral ‘8’ is used in reference to each cable essentiallydriving a single finger bi-directionally. Each finger 8 comprises apulley 9, an arm and support pad.

Each pulley 9 has an opening 10 (shown in FIG. 6) in the channels of thepulleys for terminating the cable 7 to provide bi-directional motion ofthe pulley 9 about the axis of the central body 3. Each cable 7 has twosheaths that are used to assist in providing the bi-directional motionto pulley 9 and the guidance between the motor actuators in an actuatordrive and control mechanism 11, shown schematically in FIG. 1, which ismounted remotely from the gripper 1, e.g. in a box under the hapticdevice.

An angular arm member 12 is attached to the pulley 9 and is parallel tothe central body 3 to distribute feedback, namely tactile sensation or,more preferably forces to the user's fingertips. These forces aredistributed via the finger contact point 13 which is mounted to theangular arm member 12 for rotational movement about the angular armmember 12. Arrow A, depicted in FIG. 1 represents the rotational motionabout the axis of the central body 3 so as to apply a torque about thisaxis. Further, arrow A′ is shown representing how each finger pad isable to rotate around the axis of each arm member 12 which may allowusers' fingers to move in a comfortable position especially duringgrasping and rotation exercises. The finger contact point 13 contains afinger strap 14 that ties the users thumb and forefinger to the fingercontact point 13 and as a result applies internal and external feedbackor forces to the user's fingertips.

It would be appreciated by the person skilled in the art that practicalincarnations of the first embodiment may find application in, forexample, environments that are suitable for providing telepresencealthough this is not to be taken as a limiting example of use. Intelepresence applications, the environment that a user experiences maybe real but too awkward or dangerous too actually visit. Usually someform or robot or maybe just a robotic arm may carry sensors that witnessthe environment and send information back to the user. Theseenvironments may relate to fields such as, for example, fire fighting,surgery and exploring extremely remote environments like Mars by robotand a benefit of such telepresence systems is that they can be used toextend a user's senses beyond their normal capabilities. For example, itis envisaged that infrared or ultraviolet sensors can have their outputsremapped into the visible spectrum to allow a user to see events thatmay normally be invisible and, robots fitted with radiation counters canbe used to explore inside the parts of nuclear power stations where itis unsafe for humans to be. For instance, the robot can check fordamaged areas and report the level of radiation without endangering theoperator.

A second embodiment relates to motion simulation. It will be convenientto hereinafter describe the second embodiment in relation to the use ofanthropomorphic robotic apparatus to provide a haptically enableduniversal motion simulator platform for facilitating vehicle simulationsto support training and/or research, however, it should be appreciatedthat the present invention is not limited to that application, only.

In general, the field of haptics relates to the development, testing,and refinement of tactile and force feedback devices and supportingsoftware that permit users to sense, or “feel”, and manipulate virtualobjects with respect to such attributes as shape, weight, surfacetextures, temperature and so on.

Generally, it may be stated that of the five senses, namely, sight,sound, smell, touch and taste, it is sight, sound and touch that providethe most information about an environment, where the other senses aremore subtle.

In humans, tactile sensing is generally achieved by way of receptorcells located near the surface of the skin, the highest density of whichmay be found in the hands. These receptors can perceive vibrations of upto about 300 Hz. Therefore, in a haptic interface tactile feedback maygenerally involve relatively high frequency sensations applied in theproximity of the surface of the skin, usually in response to contact, assuch, between a user and a virtual object. In contrast, the humansensing of forces may be considered as more kinesthetic in nature, andmay ordinarily be achieved by receptors situated deeper in the body.These receptors are located in muscles, tendons and joints and may bestimulated by movement and loading of a user's body parts. The stimulusfrequency of these receptors may be much lower, lying in the range ofabout 0-10 Hz. Accordingly, in a haptic interface force feedback maycomprise artificial forces exerted directly onto the user from someexternal source.

Therefore, it is considered there are two aspects to the sense of touch;firstly that which provides kinesthetic information and secondly thatwhich provides tactile information. The kinesthetic information that auser perceives about an object are coarse properties such as itsposition in space, and whether the surfaces are deformable or resilientto touch. Tactile information may be considered to convey the texture orroughness of an object being ‘touched’. It is desirable that both typesof ‘touching’ information be used in a realistic haptic interface.

Haptic Interfaces are systems that enable a user to interact with avirtual environment by sensing a user's movements and then relaying thisinformation to the virtual environment. Along side this interaction,sensory feedback is provided to the user which reflects their actionswithin this environment, and as a result, it is the design of the hapticinterface which conveys the level of sensory interactivity between theuser and the virtual environment.

In accordance with particularly preferred aspects of the secondembodiment, there is provided a haptically enabled Universal MotionSimulator (UMS) as shown in FIG. 9. The preferred UMS of FIG. 9 is aplatform for providing research and/or training via motion simulationwhich comprises, in combination, the following technologies:

-   -   High payload anthropomorphic robot 91;    -   Tracking devices for human motion capturing 1112 (best shown in        FIGS. 11 and 12);    -   Visual display systems 93;    -   Haptic system 94;    -   3D Audio systems 96;    -   Associated simulation Application programming interfaces (API)        not shown;    -   Simulation motion control software and hardware, not shown.

In the preferred UMS platform a modified pod 97 is operatively attachedto the end wrist 98 of the robot arm 99 and may be in the sameconfiguration as commercially available motion simulators, such as thatdisclosed U.S. Pat. No. 6,776,722 in the name of De-Gol and assigned toRobocoaster Limited. The device disclosed by De-Gol is marketed as theRobocoaster™.

The pod 97 is attached to the wrist 98 of the anthropomorphic robot 91via appropriate couplings such as for example a mounting flange 911. Thepod 97 may thus in effect become the end effector (tool or gripper) partof the robot 91. The robot 91 may be adapted to place or position thepod 97 in a Cartesian coordinate system anywhere in X, Y and Z plane atany orientation.

The pod 97 may comprise haptic controls (not shown) forming part of theuser interfaces for a lightweight 3D display headset (not shown) such asa head mounted display (HMD) to be worn by the user to view thesimulated world and 3D audio systems to provide aural cues. The HMD maybe equipped with ear phones for audio input. The virtual world can begenerated by suitable custom built software such as, for example, gamedevelopment engines for creating virtual worlds as would be understoodby the person skilled in the art may be used for this purpose.Accordingly, views of such virtual worlds or environments may bedisplayed on to the HMD preferably using sequential stereo for 3D depthperception to the user. Depending on the virtual world, aural cues maybe generated and can be triggered according to different events that mayoccur within the virtual world to provide a true sense of realism andimmersion for the user. To keep the motion of the UMS synchronized withthe human visual system and for any dynamic biomechanical analyses,tracking capabilities may be introduced by way of magnetic,electromagnetic and/or optical trackers 1112 as shown in FIGS. 11 and12.

The magnetic and optical trackers 1112 with their respectivecapabilities may complement each other and may generate accurateorientation and positional information at any instant of time withrespect to the orientation and position of the pod 97. At any instant oftime depending on the position (in Cartesian coordinates i.e. X, Y, Z)and orientation (in terms of yaw, pitch and role) of the pod 97, theview of the user may be transformed by a negative amount of the samevalues of X, Y, Z, yaw, pitch and role to keep the UMS synchronized withthe user's visual system.

Two parallel motion cues, defining different motion patterns, may begenerated, simultaneously, at the occurrence of any event, within thesimulation environment and can be defined as major and minor motioncues, accordingly. The major motion cues may define the overall changein position and orientation of the pod 97 from one point in space to theother, such as, in a car driving simulation, the change in position andorientation of the car from time instant t to t+ε with respect to theroad, where ε defines a small change in time. The major motion cues maybe generated by the robot arm 99 and may define the overall position andorientation of the pod 97. On the other hand, the minor motion cuesresponsible for more detailed but low intensity motion sensations forthe user, may be generated within the pod 97 preferably using hapticsactuators 94 as shown in FIG. 10c . The haptic actuators demonstrated inFIG. 10c are preferably two PHANToM™ Omni™'s, however there are manydifferent combinations and arrangements of the haptic actuators that maybe incorporated within the pod 97 as would be recognised by the personskilled in the art.

The haptics actuators 94 may also be responsible for producing forcefeedback cues to mimic real physical phenomena such as leaning outsidewith vibrations while making a turn on a rough surface road.

Thus the proposed UMS will provide a significant advancement in theresearch of simulated training and testing of operators and systems.Furthermore, it may eliminate motion sickness problems to users as aresult of reduced reliance on alignment of visual and motion cuesthrough combination of translational motion to rotary motion and the useof the same size turning radius when changing directions. This may beaccomplished by placing the pod 97 at any point in space along the X, Y,Z plane (in Cartesian coordinate) while at the same time creating roll,pitch and yaw at the wrist of the robot thereby placing the pod 97 atany orientation in space.

As noted, the Robocoaster™ system with a cage attached to the end of therobot arm is already commercially available. However the physicalmovement of the user inside the cage is constrained by the cage wallsand ceilings in these systems. It is proposed that the cage be modifiedinto a pod/cabin 97 in such a manner where the user is constrained by,for example, a five point harness and the cage itself to act as theoverall frame and super structure.

The pod 97 may also be reconfigurable to allow the UMS to be used in anumber of different applications. The interactivity between the robot 91and the human user has been taken into account to support this aim andis demonstrated schematically in FIG. 10a . FIG. 10a shows theinteractivity between the user and the robot. The module 101 is the GUI(Graphical User Interface) for the users input. The module 102 extractsthe information from the input controls triggered by the user. Themodule 103 is responsible for the visualization presented to the user.The predefined simulation environment exists in 104. Module 105 isresponsible for extracting the position and orientation information.Module 106 performs information extraction for the robot movement whichis then passed to 108 the robot control module for controlling therobot. Module 107 performs information extraction for the hapticsfeedback which is then passed to 109 Haptics feedback control module forcontrolling the haptic information. Module 1010 represented the 6 DOFrobot arm. The haptic actuators are presented by 1011, providing theoperator with haptic information in addition to the whole body hapticsensation provided by the robot arm alone. The graphics module 1012 isfor simulation environment and visualization.

The interactivity between the robot 91 and the human user may also bebased on existing motion simulator technology, such as the MediaMation™control software. One example control system package is “UniversalKinematics” from MediaMation™ to communicate with the motion controllerresponsible to drive the robot. A signal may be generated by the userthrough the user controls 1113, such as, by turning a steering wheel orpressing brake or acceleration pedals in a car driving scenariosimulation. The signals possessing different parameters, such aspositional coordinates, orientation transformation information and,linear and angular velocity components, may then be passed to the motioncontrol software to trigger the built in motion commands to thecontroller and consequently to the robot 91 to generate appropriatemotions.

In broad terms, FIG. 10 shows a flowchart diagram enabling this controlfrom user input to the robot motion. Conceptually, FIG. 10 shows:

Driving simulator+Haptics−→MediaMation™ control software

This flow of logic involves the creation of a position of the body inspace and a calculation of required velocity. Then this data is fed intothe robot controller to execute the motion for that segment. In thiscontext, ‘segment’ refers to a motion segment in the simulatedenvironment that is being translated into control action to be executedby the robot controller.

A useful feature of the preferred UMS platform is to mimic the realphysical motion scenarios by generating required smaller but highlydetailed motions within the pod/cabin 97 using haptics systems. This isachieved through the force feedback of the haptic system such as hapticmanipulator, haptic steering wheel 1113 and gearshift mechanism andreflecting the forces.

The haptics systems may generate finer detailed motions as a response tothe robot arm motion in order to provide a near real experience of thereal world scenario. An example of such a system can be the simulationof riding a high-speed motorbike, where at high-speed turn driver has tolean towards inside of the turn. In such simulated scenarios the robotarm 99 generates the overall motion but the feelings of balancing of thedriver can only be generated by haptics system.

For simulations scenarios involving dynamic biomechanical analyses andthe development of accurate human motion simulation models, an empiricalmotion database derived from efficient measurement and well-standardizeddata processing methodologies may be established. This may be obtainedfrom motion capture units stored into a database. Some research centresmay already have this data for ease of availability. The accuratemeasurements can be achieved by using electromagnetic and opticalmotion-capture systems simultaneously to record the motion data to veryhigh accuracy and robustness. In practice, the magnetic tracker 1112 canprovide the positional and orientation information of different parts ofthe body such as location of the arms and legs with bending angles ofthe joints whereas the optical tracker 1112 may provide the overallposture of the user. Both sets of information are compared andcalibrated against each other to extract the true posture of the userand consequently robust human motion data. FIG. 11 shows a setup ofhuman motion capture using electromagnetic and optical trackers 1112simultaneously. The tracking devices 1112 using the combination ofelectromagnetic and optical motion sensors can provide a degree ofvariation in the amount of kinematic information, spatial range ofmeasurement, external sources of noise, motion tracking time and spans abigger information space thus the accuracy of the human motionsimulation models can be highly improved. FIG. 12 shows a physical setupfor human motion capture using electromagnetic and optical trackers 1112simultaneously.

With reference to FIGS. 11 and 12, once the human-user input iscollected a motion controller (not shown) may be used to provide theresponse, monitoring and/or 3D graphical simulation of the robot. Thiscontroller may be based on a very advanced motion-control scheme. Thesystem control architecture is presented in FIG. 10 b.

1310 is the user interaction controls to interact with the simulationenvironment. Module 1410 tracks the user to synchronize user motion andvisualization. Physics engines 1510 control the physical behavior ofgraphics objects, while module 1610 is responsible for the registrationof graphics. The calibration module 1710 keeps the hardware andvisualization synchronized during the simulation. 1810 Controls theactuation of the robot arm. The force acquisition module 1910 triggersthe haptic feedback. 2010 represents the repository of data required forthe simulation. The simulation environment 2110 controls theinteractivity of different modules. Audio and visual feedback 2210 isgenerated to the user in response to different events within thesimulation. The graphical user interface module 2310 provides theoperator with visual information through a display 2410. The robotcontroller 2510 is responsible for controlling the final robot motion.The haptic controller 2610 is responsible for controlling the finalrobot motion. The haptic actuators 2710 provide the haptic forces tosome particular part of the operator's body.

It is capable of providing extremely quick robot responses to any low orhigh bandwidth robot commands. In practice, the motion control may be apiece of software being executed in the robot controller (not shown) toprovide the motion to the pod 97.

One attribute of the associated controller software allows thegeneration of robot trajectories that have programmable level of jointsjerk (operator comfort) and are free of sudden change of curvature.

The system may also allow full real-time access to various high andlow-level robot variables, including joints positions, joint currents,joints velocity and on-line plotting of the trajectories.

Once fully set up the system can be used as a real-time trainingsimulator capable of responding to the user input at the time the eventis occurring, and mechanically able to move in any direction at any onetime. Motion capture may be used to determine human position within thepod 97 in space. The system may use this data and the input from thehaptic devices 94 to determine the next course of action. The robot maybe adapted to respond to input signals from the haptic device.

The proposed UMS platform facility will significantly enhance theresearch and development capabilities especially for automotive industryoriented research. As the automotive industry may be one of thecornerstones of the economy worldwide or individual economies, theproposed UMS may allow the industry to keep an edge over the overseascompetitors and will significantly contribute to sustainability of agiven economy.

It would be appreciated by the person skilled in the art thatembodiments of the present invention may find application in, forexample, environments that are suitable for providing telepresencealthough this is not to be taken as a limiting example of use. Intelepresence applications, the environment that a user experiences maybe real but too awkward or dangerous too actually visit. Usually someform or robot or maybe just a robotic arm may carry sensors that witnessthe environment and send information back to the user. Theseenvironments may relate to fields such as, for example, fire fighting,surgery and exploring mars by robot and a benefit of such telepresencesystems is that they can be used to extend a user's senses beyond theirnormal capabilities. For example, it is envisaged that infrared orultraviolet sensors can have their outputs remapped into the visiblespectrum to allow a user to see events that may normally be invisibleand, robots fitted with radiation counters can be used to explore insidethe parts of nuclear power stations where it is unsafe for humans to be.For instance, the robot can check for damaged areas and report the levelof radiation without endangering the operator.

A third described embodiment relates, in one form, to haptic technologyand its use for the control of mobile platforms, “Mobile platform”refers to systems which have the capability to move from one place toanother. Such platforms include, but are not limited to, mobile roboticsystems, passenger ground vehicles and un-manned airborne vehicles.

FIG. 13 illustrates haptic systems 138 according to the third embodimentof the present invention. The module 139 illustrates components of thesystem 138 that would normally be mounted aboard a mobile platform suchas platform 2 a as shown in FIG. 1a . The module 1311 illustrates thecomponents of the system 138 that would normally be mounted proximatethe user, including within the haptic probe 3 a as shown in FIG. 1 a.

The module 139 comprises a micro-controller 1312 together with a motioncontroller 1313, a PID (proportional-integral-differential) motorcontroller 1314, monitors and encoders 1316, an on-board camera 1317, aGPS receiver 1318 and a 6-axis inertial measurement unit (IMU) 1319,sonar sensors 1321 and ASHA module 1322.

These components comprising module 139 may operate on the platform 2 aof FIG. 1a . The program code on the micro-controller 1312 isresponsible for preprocessing and control of low-level sensory systemssuch as the sonar sensors 1321. The PID motor controller 1314 is its ownhardware module. The motion controller 1313 and ASHA module 1322 existin executable program code on the platforms embedded computer. The ASHAmodule 1322 receives all the required information from the motioncontroller 1313, PID motor controller 1314, sonar sensors 1321 (viamicrocontroller 1312), GPS 1318 and the 6-axis IMU 1319. The motioncontroller 1313, acting under control of the ICHA 1323, generates motioncontrol settings which are sent to the PID motor controller 1314. ThePID motor controller 1314 then achieves closed loop control of themotors 1316 based on the encoder feedback 1316.

The sensory systems on the mobile platform comprise the 6-axis IMU 1319,GPS 1318 and sonar sensors 1321. The GPS 1318 and IMU 1319 directlyinterface to the ASHA module 1322 (software implementation on onboardcomputer) using serial RS-232 communication. The sonar sensors 1321 arecontrolled by the microcontroller 1312 which then transmits theappropriate sensory information to the ASHA module 1322 (softwareimplementation on onboard computer) using serial RS-232 communication.

The operator control module 1311 comprises a suitable haptic interface1324 (such as the haptic device 3 a illustrated in FIG. 1a ) and aninput haptic control augmentation (ICHA/IHCCS) 1323. The hapticinterface 1324 receives physical inputs (such as movement of the probe 5a of FIG. 1a ) from the operator and delivers haptic augmentation backto the operator. The construction and operation of the ICHA 1323, andits interactions with the haptic interface 1324, are described in moredetail below.

FIG. 14 illustrates a haptically-rendered control surface 26 that ispresented to the user in accordance with the third preferred embodimentof the present invention.

According to the presently-described embodiment of the invention, thehaptically-rendered virtual surface 26 is achieved using off-the-shelfhardware and appropriate control software. The haptically-renderedvirtual surface 26, can be “felt” or “touched” by the user depending onthe particular implemented haptic device. Suitable devices include butare not limited to, the Phantom™ Omni™ Desktop and Premium devices; andthe Falcon™ from Novint™ Technologies.

The preferred shape of the haptic control surface 26 is designed toserve as an indicator to the operator of the values of commanded inputlinear velocity “v” and angular velocity “w” of a remote platform. Thatis, the shape of the haptic control surface 26 is defined by thefollowing equation:

[(k ₁ ·v)²+(k ₂·ω)²]^(1/2) =k ₃ ·z  (1)

where

-   -   k₁ and k₂ scale the appropriate ranges of v and ω relative to        each other    -   k₃ is a constant related to the slope of that particular cone;        and

Given appropriate values of k₁, k₂ and k₃, the z value (height) for anypoint (v, ω) is given by

z=[(k ₁ ·v)²+(k ₂·ω)2]^(1/2) /k ₃  (2)

Subject to the maximum desired linear (v) and angular (ω) velocities

[(k ₁·Maxv)²+(k ₂·Maxω)²]^(1/2) =k ₃·Maxz  (3)

where

-   -   Max v and Max ω represent the desired maximum platform        velocities

Considering the use of the Phantom™ Omni™ by Sensable Technologies(http://www.sensable.com/) and the Pioneer™ P3DX Mobile Robot(http://www.activrobots.com/ROBOTS/p2dx.html) as a specific combinationof hardware devices.

The Phantom™ Omni™ offers a usable haptic workspace of 160 W×120 H×70 D.The Pioneer™ P3DX offers a maximum published linear velocity (v) of 1.6metres-per-second. The suitable angular velocity (w) needs to bedetermined empirically, however for the purposes of explanation weconsider a feasible maximum angular velocity to be 0.5 full rotations(180 degrees) per second. It also needs to be considered that in realitythe maximum individual linear and angular velocities may not beachievable when including significant contributions of each another.

As such, we consider the maximum linear velocity of 1 metre per secondand angular velocity of 0.25 full rotations a second. The scalingfactors of k₁, k₂ serve two purposes, to scale k₁ and k₂ relative toeach other and to scale the dimensions to that of the workspace of theimplemented haptic device. The device offers a workspace of 160 W×120H×70 D, representing the ω, v, height dimensions respectively (see FIG.14), and as, such the depth of 70 mm is the limiting factor. Choosing anominal 65 mm range along both the ω and v axes, k1 and k2 are chosenappropriately where:

for ω, 0.25*k2=66/2

and v, 1*k1=65/2

which satisfies

[(k1·Maxv)2+(k2·Maxω)2]½=k3·Maxz

where k3 is chosen appropriately.

Implementation of ICHA Independent of ASHA

When the ICHA is to be considered independently, there are alternativepreferred methodologies to render the required virtual haptic surface.One suitable method to render the virtual haptic conical surfaceprovides force rendering in the Z-direction only. Given an actual Zposition, given by Z_(actual) and a desired Z position given by equation2, the difference (between Z position, given by Z_(actual)) can be usedby a variety of control techniques to render the desired surface. Thereare various proven techniques for rendering haptic surfaces and thedisplay of haptic forces to a user. Such methods include the use ofmass-spring-damper, mass-string and spring models, andproportional-integral-control (PID). The actual method employed dependson various factors such as the characteristics of the employed hapticdevice, whether the device software libraries provide such pre-builtsoftware functions, etc, as well as the desired stiffness or hardness ofthe rendered conical surface. In general, the position of the hapticprobe (x, y, z) needs to be monitored and the appropriate forcesapplied, given the implemented control strategy. There are variousproven control methods for rendering such surfaces.

FIG. 17 demonstrates the difference between the existing 2-D planarhaptic control surface (http://citeseer.ist.psu.edu/705176.html) and the3-D ICHA described above. In FIG. 17, v and ω denote the linear andangular velocities respectively of a platform 2 a as shown in FIG. 1a .As is shown in FIG. 17, the orthogonal displacements of a haptic probe 3a of FIG. 1a from the origin in two dimensions signify the values ofcommanded input linear and angular velocities to the remote platform. Incontrast, as described above with reference to equations (1), (2) and(3) and FIG. 14, according to the third embodiment of the presentinvention the user is constrained to move the input probe 3 a inconformity with a three-dimensional surface in which the displacement ofthe probe in the third dimension (the height Z in FIG. 14) is alsoindicative of the values of linear and angular velocity.

FIGS. 17a and 15 illustrate differences in performance between the priorart arrangement of FIG. 17 and the third embodiment of the presentinvention according to FIG. 14.

In particular, FIG. 15 demonstrates the operator's ability to return thecommand input to a zero motion state using an ICHA according to FIG. 14.In providing motion commands the operator can exploit the geometry ofthe cone in returning to a 0,0,0 position. When an operator hasexperience in operating with a surface of a given gradient, then theoperator will be able to judge the commanded velocity, based on thevertical displacement of the haptic probe. It will be seen from FIGS.17a and 15 that, using ICHA according to the third embodiment of thepresent invention, the actual angular and linear velocities of theremote platform 2 a both simultaneously return directly to zero whereasin the system according to FIG. 17, there is overshoot of linear andangular velocities both overshoot zero before coming back to zero.

The preferred conical form of the ICHA provides unique attributes to auser who is controlling the motion of a mobile platform. The geometricproperties of a cone result in convergence to a particular point on thehaptically rendered control surface. The user is easily able todetermine a zero velocity command state by following the conical surfaceto its point of convergence. Additionally the gradient of cone surfaceprovides the user, particularly an experienced user, with an indicationof the current commanded velocity. When an operator has experience inoperating with a surface of a given gradient, then the operator will beable to judge the commanded velocity, based on the vertical displacementof the haptic probe.

Implementation of ICHA Integrated with ASHA

According to alternative aspects of the third preferred embodiment ofthe invention, ICHA and ASHA are integrated and presented to theoperator by way of a single haptically-rendered control surface 26.

When the motion of the remote platform 2 a is such that there is no ASHAbeing generated, movement of the haptic probe over the virtual surface26 is unopposed, subject only to the constraint imposed on movement bythe maximum limits of angular and linear velocity. When the motion ofthe remote platform 2 a is such that it is necessary to provide ASHA tothe operator, it is the case that the user can easily recognize theforces implementing the ASHA and readily distinguish the ASHA from theICHA.

Given that a haptic device needs to be adequately programmed tohaptically render any virtual surfaces and/or forces in order toimplement this approach, there are two components requiringconsideration. These are the haptic rendering of the ICHA and thesimultaneous haptic rendering of the ASHA. As such, in implementation ofthis approach, any instantaneous rendered haptic force will be anappropriate simultaneous combination of the force required to render theICHA as well any required ASHA. There are several different possibleapproaches which may be taken to render the required virtual hapticsurface. One preferred method for determining the actual force requiredto render the haptic augmentation acting across the ICHA is thevectorial combination of haptically rendered forces. This is explainedin further in FIG. 16, where F_(b) denotes the haptic augmentation forcecomponents and F_(a) denotes the ICHA force components.

FIG. 18 shows a flow-chart which illustrates the processing 1800 toprovide both ICHA and AHSA.

At step 1802, the haptic device is initialized.

At step 1803, the parameters of the ICHA are ascertained. Theseparameters comprise the maximum linear velocity Max v, the maximumangular velocity Max ω and the scaling factors k₁, k₂, k₃.

At step 1804 a decision is made whether ASHA is required. If ASHA isrequired, then the magnitude of the force components in the w and vdirections are received from ASHA (Step 1805), if ASHA is not required,then the force components of the ASHA are zero (Step 1806).

At step 1807 we determine the force required render the ICHA alone.

At step 1808 we determine the resultant force combining ICHA and ASHA

At step 1809 the resultant haptic forces are rendered.

While the present invention has been described with reference to a fewspecific embodiments, the description is illustrative of the inventionand is not to be construed as limiting the invention. Variousmodifications may occur to those skilled in the art without departingfrom the true spirit and scope of the invention as defined by theappended claims. For example, a person skilled in the art will recognisethat embodiments of the invention described herein may be implementedusing one or more computers. In that case, the method steps disclosedherein may be embodied as instructions that comprise a computer program.The program may be stored on computer-readable media, such as floppydisks, optical discs (eg compact discs), or fixed disks (such as harddrives and the like), and may be resident in memory, such as, forexample random access memory (RAM), read-only memory (ROM), firmware, orflash RAM memory. The program as software may then be executed on acomputer or microprocessor device to implement the method. The programor portions of its execution, may also be distributed over multiplecomputers or servers in a network having a topology corresponding to oneor a combination of: a small area such as in a LAN (Local Area Network);a large campus or city area such as in a MAN (Metropolitan Area Network)or; a wide geographical area such as in a WAN (Wide Area Network). As anexample, the first embodiment described herein may be suitable for usewith a computer network implementation of a quality assurance (QA) ormaintenance system for diagnosing faults and servicing modules orinstruments to effect service and repairs and upgrades to instrumentsoftware from a remote platform or a central controller ormicro-controller.

It should be noted that where the terms “server”, “secure server” orsimilar terms are used herein, a communication device is described thatmay be used in a communication system, unless the context otherwiserequires, and should not be construed to limit the present invention toany particular communication device type. Thus, a communication devicemay comprise, without limitation, a bridge, router, bridge-router(router), switch, node, or other communication device, which may or maynot be secure.

It should also be noted that where a flowchart, set of rules or theirequivalent is used herein to demonstrate various aspects of theinvention, it should not be construed to limit the present invention toany particular logic flow or logic implementation. The described logicmay be partitioned into different logic blocks (e.g., programs, modules,functions, or subroutines) without changing the overall results orotherwise departing from the true scope of the invention. Often, logicelements may be added, modified, omitted, performed in a differentorder, or implemented using different logic constructs (e.g., logicgates, looping primitives, conditional logic, and other logicconstructs) without changing the overall results or otherwise departingfrom the true scope of the invention.

Various embodiments of the invention may be embodied in many differentforms, comprising computer program logic for use with a processor (e.g.,a microprocessor, microcontroller, digital signal processor, or generalpurpose computer), programmable logic for use with a programmable logicdevice (e.g., a Field Programmable Gate Array (FPGA) or other PLD),discrete components, integrated circuitry (e.g., an Application SpecificIntegrated Circuit (ASIC)), or any other means comprising anycombination thereof. In an exemplary embodiment of the presentinvention, predominantly all of the communication between users and theserver is implemented as a set of computer program instructions that isconverted into a computer executable form, stored as such in a computerreadable medium, and executed by a microprocessor under the control ofan operating system.

Computer program logic implementing all or part of the functionalitywhere described herein may be embodied in various forms, comprising asource code form, a computer executable form, and various intermediateforms (e.g., forms generated by an assembler, compiler, linker, orlocator). Source code may comprise a series of computer programinstructions implemented in any of various programming languages (e.g.,an object code, an assembly language, or a high-level language such asFortran, C, C++, JAVA, or HTML) for use with various operating systemsor operating environments. The source code may define and use variousdata structures and communication messages. The source code may be in acomputer executable form (e.g., via an interpreter), or the source codemay be converted (e.g., via a translator, assembler, or compiler) into acomputer executable form.

The computer program may be fixed in any form (e.g., source code form,computer executable form, or an intermediate form) either permanently ortransitorily in a tangible storage medium, such as a semiconductormemory device (e.g, a RAM, ROM, PROM, EEPROM, or Flash-ProgrammableRAM), a magnetic memory device (e.g., a diskette or fixed disk), anoptical memory device (e.g., a CD-ROM or DVD-ROM), a PC card (e.g.,PCMCIA card), or other memory device. The computer program may be fixedin any form in a signal that is transmittable to a computer using any ofvarious communication technologies, including, but in no way limited to,analog technologies, digital technologies, optical technologies,wireless technologies (e.g., Bluetooth), networking technologies, andinter-networking technologies. The computer program may be distributedin any form as a removable storage medium with accompanying printed orelectronic documentation (e.g., shrink wrapped software), preloaded witha computer system (e.g., on system ROM or fixed disk), or distributedfrom a server or electronic bulletin board over the communication system(e.g., the Internet or World Wide Web).

Hardware logic (comprising programmable logic for use with aprogrammable logic device) implementing all or part of the functionalitywhere described herein may be designed using traditional manual methods,or may be designed, captured, simulated, or documented electronicallyusing various tools, such as Computer Aided Design (CAD), a hardwaredescription language (e.g., VHDL or AHDL), or a PLD programming language(e.g., PALASM, ABEL, or CUPL).

Programmable logic may be fixed either permanently or transitorily in atangible storage medium, such as a semiconductor memory device (e.g., aRAM, ROM, PROM, EEPROM, or Flash-Programmable RAM), a magnetic memorydevice (e.g., a diskette or fixed disk), an optical memory device (e.g.,a CD-ROM or DVD-ROM), or other memory device. The programmable logic maybe fixed in a signal that is transmittable to a computer using any ofvarious communication technologies, including, but in no way limited to,analog technologies, digital technologies, optical technologies,wireless technologies (e.g., Bluetooth), networking technologies, andinternetworking technologies. The programmable logic may be distributedas a removable storage medium with accompanying printed or electronicdocumentation (e.g., shrink wrapped software), preloaded with a computersystem (e.g., on system ROM or fixed disk), or distributed from a serveror electronic bulletin board over the communication system (e.g., theInternet or World Wide Web).

As the present invention may be embodied in several forms withoutdeparting from the spirit of the essential characteristics of theinvention, it should be understood that the above described embodimentsare not to limit the present invention unless otherwise specified, butrather should be construed broadly within the spirit and scope of thepresent invention as defined in the appended claims. Variousmodifications and equivalent arrangements are intended to be includedwithin the spirit and scope of the present invention and appendedclaims. Therefore, the specific embodiments are to be understood to beillustrative of the many ways in which the principles of the presentinvention may be practiced. For example, although a haptic device hasbeen described herein in certain embodiments as capable of interacting(or reading and writing) to and from the human hand, it may also beappreciated that such a device may be designed to read and write to andfrom the human foot or some other part of the body whilst stillembodying embodiments of the present invention. Furthermore, thosefamiliar with the haptic arts will recognize that there are manydifferent haptic interfaces that convert the motion of an object underthe control of a user to electrical signals, many different hapticinterfaces that convert force signals generated in a computer tomechanical forces that can be experienced by a user, and hapticinterfaces that accomplish both results, each and every one of which maybe encompassed by the present invention.

In the following claims, means-plus-function clauses are intended tocover structures as performing the defined function and not onlystructural equivalents, but also equivalent structures. For example,although a nail and a screw may not be structural equivalents in that anail employs a cylindrical surface to secure wooden parts together,whereas a screw employs a helical surface to secure wooden partstogether, in the environment of fastening wooden parts, a nail and ascrew are equivalent structures.

“Comprises/comprising” when used in this specification is taken tospecify the presence of stated features, integers, steps or componentsbut does not preclude the presence or addition of one or more otherfeatures, integers, steps, components or groups thereof.”

1.-24. (canceled)
 25. A method of simulating motion, the methodcomprising the steps of: providing at least six degrees of freedom ofmovement to a user by operatively associating an anthropomorphic robotarm with a user pod for receiving the user; and providing hapticfeedback to the user in correspondence with the movement of the userpod.
 26. A method as claimed in claim 25 further comprising one or acombination of the following steps of: providing the user with aperception of a simulated environment; and, tracking the motion of theuser;
 27. A method as claimed in claim 26 wherein the step of providinghaptic feedback comprises: feeding back the tracked motion of the userto an interface for adapting the user's perception of the simulatedenvironment.
 28. A method as claimed in claim 27 wherein the step offeeding back comprises transforming the user's view by a negative amountthat compliments the tracked motion.
 29. A method as claimed in claim 26wherein the tracked motion comprises one or a combination of: positionin Cartesian coordinates X, Y and Z; and, orientation comprising yaw,pitch and roll.
 30. A method as claimed in claim 25 further comprisingthe step of providing one or a combination of: at least one major motioncue generated by the robot arm and corresponding to a position and/ororientation of the pod; at least one minor motion cue generated by atleast one haptic actuator provided in the pod and operatively associatedwith the user; and at least one force feedback cue generated by the atleast one haptic actuator for simulating physical phenomena encounteredby the user in a simulated environment.
 31. A method as claimed in claim25 further comprising the step of: operatively associating a softwarecontrol to relate a plurality of simulated environment applications witha motion controller of the robot arm.
 32. A method as claimed in claim31 wherein the step of operatively associating the software control withthe motion controller comprises the steps of: generating user controlsignals associated with pod devices controlled by the user andcomprising motion parameters; communicating the control signals to thesoftware control for triggering motion commands for the robot arm.
 33. Amethod as claimed in claim 25 further comprising the step of one or acombination of: generating an empirical motion database comprisingcaptured motion data for simulating predetermined simulation scenariosand/or modelling; accessing an existing empirical motion databasecomprising captured motion data for simulating predetermined simulationscenarios and/or modelling.
 34. A method as claimed in claim 26 whereinmotion tracking comprises one or a combination of positional and/ororientational information of the user's body and/or body parts and isobtained by one or a combination of: magnetic; electromagnetic; and,optical motion capture means.
 35. Motion simulator apparatus comprising,in combination: an anthropomorphic robot arm adapted to provide at leastsix degrees of freedom of movement; a user pod for receiving a user,said user pod being operatively connected to the anthropomorphic robotarm; and a haptic interface operatively associated with the user pod forproviding haptic feedback to the user in correspondence with themovement of the user pod.
 36. Apparatus as claimed in claim 35 furthercomprising: a user control interface operatively associated with the podand the robot arm for providing a user with a perception of a simulatedenvironment; and; tracking devices for tracking the motion of the user.37. Apparatus as claimed in claim 36 wherein the haptic interface isadapted for feeding back the tracked motion of the user to the usercontrol interface for adapting the user's perception of the simulatedenvironment.
 38. Apparatus as claimed in claim 37 further comprisingtransforming means for transforming the user's view by a negative amountthat compliments the tracked motion.
 39. Apparatus as claimed in claim36 wherein the tracked motion comprises one or a combination of:position in Cartesian coordinates X, Y and Z; and, orientationcomprising yaw, pitch and roll.
 40. Apparatus as claimed in claim 35wherein the apparatus is adapted to provide one or a combination of: atleast one major motion cue generated by the robot arm and correspondingto a position and/or orientation of the pod; at least one minor motioncue generated by at least one haptic actuator provided in the pod andoperatively associated with the user; and at least one force feedbackcue generated by the at least one haptic actuator for simulatingphysical phenomena encountered by the user in a simulated environment41. Apparatus as claimed in claim 35 further comprising: a computerproduct comprising a software control to relate a plurality of simulatedenvironment applications and adapted for operative association with amotion controller of the robot arm.
 42. Apparatus as claimed in claim 41wherein the software control is operatively associated with the motioncontroller by: user control signal generating means for generating usercontrol signals associated with pod devices controlled by the user andcomprising motion parameters; communication means for communicating thecontrol signals to the software control for triggering motion commandsfor the robot arm.
 43. Apparatus as claimed in claim 35 furthercomprising one or a combination of: an empirical motion databasegenerated in situ and comprising captured motion data for simulatingpredetermined simulation scenarios and/or modelling; and accessing meansfor accessing an existing empirical motion database comprising capturedmotion data for simulating predetermined simulation scenarios and/ormodelling.
 44. Apparatus as claimed in claim 36 wherein tracked motioncomprises one or a combination of positional and/or orientationalinformation of the user's body and/or body parts and is obtained by oneor a combination of: magnetic; electromagnetic; and, optical motioncapture means.
 45. Apparatus adapted to simulate motion, said apparatuscomprising: processor means adapted to operate in accordance with apredetermined instruction set, said apparatus, in conjunction with saidinstruction set, being adapted to perform the method as claimed in claim25.
 46. A computer program product comprising: a non-transitory computerusable medium having computer readable program code and computerreadable system code embodied on said medium for simulating motionwithin a data processing system, said computer program productcomprising: computer readable code within said computer usable mediumfor performing the steps of claim
 25. 47.-60. (canceled)